Custom Index Label problem

There is no problem getting the values but I can not get the lables right.

I have 4 instances with label oid's

1.3.6.1.4.1.2620.1.1.25.5.1.2.1.0 = DMZ

1.3.6.1.4.1.2620.1.1.25.5.1.2.2.0 = Internal

1.3.6.1.4.1.2620.1.1.25.5.1.2.3.0 = External

1.3.6.1.4.1.2620.1.1.25.5.1.2.4.0 = Lan1

I fill out 1.3.6.1.4.1.2620.1.1.25.5.1.2 in the instance label field

When I test I see my instances in like [interface::.1].[interface::.0] And I was expecting something like [interface::DMZ].[interface::.0]

When I fill out 1.3.6.1.4.1.2620.1.1.25.5.1.2.1 for example I do only get the label for 1 instance(DMZ) not for the other instances and so I should make a seperate instance for all instances only to get the label.....

The problem actualy seems to be the 0 at the end of the oid.

I tried stuff like 1.3.6.1.4.1.2620.1.1.25.5.1.2:0 as a instance label field without result.

Does anyone know how to get the labels when the OID ends in 0 for each instance instead of the index number?